diff --git a/NULL.c b/NULL.c
new file mode 100644
index 0000000000000000000000000000000000000000..a914a46637147b487a2cce460c336085a3d228bd
--- /dev/null
+++ b/NULL.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+// 真亦假，假亦真
+#define true  false
+#define false true
\ No newline at end of file